The Leuven Ring Problem ○
During my studies, I spent one semester at KU Leuven. There is one interesting mathematical problem from those times I’d like to share. This Belgian city has a topology of a big circle with a city inside. One early, cold, damp, and windy morning (as it is in Belgium) when I was coming back from some trip I had to go from the railway station (right side of the ring) to my dormitory (bottom of the ring). As shown on the map, the distance was 1/3 circumference of the Leuven ring. The question I asked myself is whether or not I should cross the street. ...